1. Field of the Invention
The field of the invention relates generally to the field of identity verification, and more particularly, to signature verification.
2. Background of the Invention
Signature verification is an important tool used to verify identity in a number of situations. For example, it is common to verifying a signature or signatures on financial instruments, including, for example, checks. Other forms of identity verification exist, but unfortunately identity theft is on the rise. Conventional forms of identity verification, including matching the appearance of two or more signatures, have drawbacks. For example, in some cases forgers can duplicate the appearance of a person's signature.
Signature verification is made more difficult by the fact that a person's signature can vary. In other words, the same person can sign his or her signature multiple times and the signatures will, in many cases, not be identical. Although signing a signature is a trained, highly automated and basic motor function skill it does not lead to identical signatures. It will be appreciated, for example, that individual's signature varies over time, typically becoming more abbreviated and/or sloppier.
Additionally, handwritten signatures can vary widely from individual to individual. Some people's signatures can be barely readable, while other people's signatures can be made up of easily read block letters. Perhaps the majority of signatures fall in between these two extremes.
Signature verification systems, therefore, have to allow for a wide range of variability including variability from signature to signature of one individual and the variability of different types and styles of signature from individual to individual.
To make the task of signature verification even more complex, electronic signature pads have been introduced by a variety of merchants and enterprises. Such devices allow for the capture of more data related to the signature. For example, time, spatial, and spectral information can be recorded for a signature using such devices. Unfortunately, these types of data also vary widely over time and between individuals, which increases the complexity of signature verification. Many conventional signature verification systems are unable to make use of such data to effectively verify authentic signatures, and reject false signatures, to the degree necessary.